From: Bin Liu b-liu@ti.com

Currently in omap_8250_shutdown, the dma->rx_running flag is set to zero in omap_8250_rx_dma_flush. Next pm_runtime_get_sync is called, which is a runtime resume call stack which can re-set the flag. When the call omap_8250_shutdown returns, the flag is expected to be UN-SET, but this is not the case. This is causing issues the next time UART is re-opened and omap_8250_rx_dma is called. Fix by moving pm_runtime_get_sync before the omap_8250_rx_dma_flush.

cc: stable@vger.kernel.org Fixes: 0e31c8d173ab ("tty: serial: 8250_omap: add custom DMA-RX callback") Signed-off-by: Bin Liu b-liu@ti.com [Judith: Add commit message] Signed-off-by: Judith Mendez jm@ti.com Reviewed-by: Kevin Hilman khilman@baylibre.com Tested-by: Kevin Hilman khilman@baylibre.com --- Issue seen on am335x devices so far [0]. The patch has been tested with sanity boot test on am335x EVM, am335x-boneblack and am57xx-beagle-x15.

Changes since v1 RESEND: - Fix email header and commit description length - Add fixes tag, add link [0], cc stable, add kevin's reviewed-by/tested-by's - Separate patch from patch series [1]

[0] https://e2e.ti.com/support/processors-group/processors/f/processors-forum/13...

Link to v1 RESEND: [1] https://lore.kernel.org/linux-omap/20241011173356.870883-1-jm@ti.com/ --- drivers/tty/serial/8250/8250_omap.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/tty/serial/8250/8250_omap.c b/drivers/tty/serial/8250/8250_omap.c index 88b58f44e4e97..0dd68bdbfbcf7 100644 --- a/drivers/tty/serial/8250/8250_omap.c +++ b/drivers/tty/serial/8250/8250_omap.c @@ -776,12 +776,12 @@ static void omap_8250_shutdown(struct uart_port *port) struct uart_8250_port *up = up_to_u8250p(port); struct omap8250_priv *priv = port->private_data;

+ pm_runtime_get_sync(port->dev); + flush_work(&priv->qos_work); if (up->dma) omap_8250_rx_dma_flush(up);

- pm_runtime_get_sync(port->dev); - serial_out(up, UART_OMAP_WER, 0); if (priv->habit & UART_HAS_EFR2) serial_out(up, UART_OMAP_EFR2, 0x0);